Method of making a write head before read head constructed merged magnetic head with track width and zero throat height defined by first pole tip

ABSTRACT

A method makes a merged magnetic head that has an air bearing surface and read and write head portions wherein the write head portion has a pole tip, yoke and back gap regions. A method of making the write head comprises steps of forming first and second pole pieces wherein the first pole piece has a first pole tip and the second pole piece has a second pole tip, forming a gap layer which separates the pole tips in the pole tip region and connecting the first and second pole pieces in the back gap region, forming an insulation stack with a write coil embedded therein between the first and second pole pieces in the yoke region and forming the first pole tip with a width at the air bearing surface that defines a track width of the write head portion. The read head portion is formed on the write head portion with a first shield layer which is a common layer with the second pole piece.

REFERENCE TO RELATED APPLICATION

This is a divisional application of application Ser. No. 09/058,521filed Apr. 10, 1998 now U.S. Pat. No. 6,130,809 issued Oct. 10, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a write head before read headconstructed merged magnetic head with the track width and the zerothroat height of the write head being defined by a first pole tip andmore particularly to a magnetic head wherein a first pole tip of a firstpole piece is frame plated on a planarized surface so as to accuratelydefine the track width of the write head with high resolution andwherein planarization after constructing the first pole tip reducesseparation between read and write gaps of the magnetic head.

2. Description of the Related Art

An inductive write head includes a coil layer embedded in first, secondand third insulation layers (insulation stack), the insulation stackbeing located between first and second pole piece layers. A gap isformed between the first and second pole piece layers by a gap layer atan air bearing surface (ABS) of the write head. The pole piece layersare connected at a back gap. Currents are conducted through the coillayer, which produce magnetic fields in the pole pieces. The magneticfields fringe across the gap at the ABS for the purpose of writing bitsof magnetic field information in tracks on moving media, such as incircular tracks on a rotating magnetic disk or longitudinal tracks on amoving magnetic tape.

The second pole piece layer has a pole tip portion which extends fromthe ABS to a flare point and a yoke portion which extends from the flarepoint to the back gap. The flare point is where the second pole piecebegins to widen (flare) to form the yoke. The placement of the flarepoint directly affects the magnitude of the magnetic field produced towrite information on the recording medium. Since magnetic flux decays asit travels down the length of the narrow second pole tip, shortening thesecond pole tip will increase the flux reaching the recording media.Therefore, performance can be optimized by aggressively placing theflare point close to the ABS.

Another parameter important in the design of a write head is thelocation of the zero throat height (ZTH). The zero throat height is thelocation where the first and second pole pieces first separate from oneanother after the ABS. ZTH separation is imposed by an insulation layer,typically the first insulation layer in the insulation stack. Fluxleakage between the first and second pole pieces is minimized bylocating the ZTH as close as possible to the ABS.

Unfortunately, the aforementioned design parameters require a tradeoffin the fabrication of the second pole tip. The second pole tip should bewell-defined in order to produce well-defined written tracks on therotating disk. Poor definition of the second pole tip may result inoverwriting of adjacent tracks. A well-defined second pole tip shouldhave parallel planar side walls which are perpendicular to the ABS. Thisdefinition is difficult to achieve because the second pole tip istypically formed along with the yoke after the formation of the firstinsulation layer, the coil layer and the second and third insulationlayers. Each insulation layer includes a hard-baked photoresist having asloping front surface.

After construction, the first, second and third insulation layerspresent front sloping surfaces which face the ABS. The ZTH defininglayer rises from a plane normal to the ABS at an angle (apex angle) tothe plane. After hard baking of the insulation layers and deposition ofa metallic seedlayer the sloping surfaces of the insulation layersexhibit a high optical reflectivity. When the second pole tip and yokeare constructed, a thick layer of photoresist is spun on top of theinsulation layers and photo patterned to shape the second pole tip,using the conventional photo-lithography technique. In thephoto-lithography light imaging step, ultraviolet light is directedvertically through slits in an opaque mask, exposing areas of thephotoresist which are to be removed by a subsequent development step.One of the areas to be removed is the area where the second pole piece(pole tip and yoke) is to be formed by plating. Unfortunately, whenultraviolet light strikes the sloping surfaces of the insulation layersin a flaring region of the second pole piece, the ultraviolet light isreflected forward, toward the ABS, into photoresist areas at the sidesof the second pole tip region. After development, the side walls of thephotoresist extend outwardly from the intended ultraviolet pattern,causing the pole tip plated therein to be poorly formed. This is called“reflective notching”. As stated hereinabove this causes overwriting ofadjacent tracks on a rotating disk. It should be evident that, if theflare point is recessed far enough into the head, the effect ofreflective notching would be reduced or eliminated since it would occurbehind the sloping surfaces. However, this solution produces a longsecond pole tip which quickly reduces the amount of flux reaching therecording medium.

The high profile of the insulation stack causes another problem afterthe photoresist is spun on a wafer. When the photoresist is spun on awafer it is substantially planarized across the wafer. The thickness ofthe resist in the second pole tip region is higher than other regions ofthe head since the second pole tip is substantially lower on the waferthan the yoke portion of the second pole piece. During the lightexposure step the light progressively scatters in the deep photoresistlike light in a body of water causing poor resolution during the lightexposure step.

A scheme for minimizing the reflective notching and poor resolutionproblems is to construct the second pole piece with bottom and topsecond pole tips. The bottom second pole tip is constructed before theinsulation layers to eliminate the reflective notching problem. Afterforming the first pole piece layer and the write gap layer, aphotoresist layer is spun on the partially completed head. Ultravioletlight from the photo-patterning step is not reflected forward since thephotoresist layer does not cover an insulation stack. Further, thephotoresist is significantly thinner in the pole tip region so thatsignificantly less light scattering takes place. After plating thebottom second pole tip the photoresist layer is removed and the firstinsulation layer, the coil layer and the second and third insulationlayers are formed. The top second pole tip is then stitched (connected)to the bottom second pole tip and extends from the ABS to the back gap.Since the bottom second pole tip is well-formed, well-formed notches canbe made in the first pole piece, as discussed hereinafter. However, withthis head, the ZTH is dependent upon the location of the recessed end ofthe bottom second pole tip. Since the bottom second pole tip has to belong enough to provide a sufficient stitching area, this length mayresult in undesirable flux leakage between the first and second polepieces. Since the top second pole tip is typically wider than the bottomsecond pole tip, the second pole piece has a T-shape at the ABS. Theupright portion of the T is the front edge of the bottom second poletip, and the cross of the T is the front edge of the top second poletip. A problem with this configuration is that during operation, fluxfringes from the outer corners of the top second pole tip to a muchwider first pole piece at the ABS, causing adjacent tracks to beoverwritten.

Once the bottom second pole tip is formed, it is desirable to notch thefirst pole tip of the first pole piece opposite the first and secondcorners at the base of the bottom second pole tip so that flux transferbetween the pole tips does not stray beyond the track width defined bythe bottom second pole tip. Notching provides the first pole piece witha track width that substantially matches the track width of the bottomsecond pole tip. A prior art process for notching the first pole pieceentails ion beam milling the gap layer and the first pole piece,employing the bottom second pole tip as a mask. The gap layer istypically alumina and the first and second pole pieces and pole tips aretypically Permalloy (NiFe). The alumina mills more slowly than thePermalloy; thus the top of the bottom second pole tip and a top surfaceof the first pole piece are milled more quickly than the gap layer.Further, during ion milling, there is much redeposition (redep) ofalumina on surfaces of the workpiece. In order to minimize redep, themilling ion beam is typically directed at an angle to a normal throughthe layers, which performs milling and cleanup simultaneously. The gaplayer in the field remote from the first and second corners of thebottom second pole tip is the first to be milled because of a shadowingeffect at the first and second corners caused by the bottom second poletip when the ion beam is angled. In this case, the ion stream willovermill the first pole piece before the gap layer is removed adjacentthe first and second corners of the bottom second pole tip in the regionwhere the notching is to take place. After the gap layer is removedabove the sites where the notching is to take place, ion millingcontinues in order to notch the first pole piece. Overmilling of thefirst pole piece continues to take place in the field beyond thenotches, thereby forming surfaces of the first pole piece that slopedownwardly from the notches. As is known, such overmilling of the firstpole piece can expose leads to the MR sensor, thereby rendering the headinoperative.

Even if overmilling of the first pole piece can be controlled, there ispotentially a more troublesome problem, namely overmilling the top ofthe bottom second pole tip when the unwanted portions of the gap layerare milled and notches are formed. In order to compensate for thisovermilling, the aspect ratio (ratio of thickness of photoresist totrack width of the bottom second pole tip) is increased so that a topportion of the top of the bottom second pole tip can be sacrificedduring the milling steps. When the aspect ratio is increased, definitionof the bottom second pole tip is degraded because of the thickness ofthe photoresist, discussed hereinabove, resulting in track overwriting.

Another problem with the prior art merged MR head is that the profile ofthe MR sensor between the first and second gap layers is replicatedthrough the second shield/first pole piece layer to the write gap layercausing the write gap layer to be slightly curved concave toward the MRsensor. When the write head portion of the merged MR head writes datathe written data is slightly curved on the written track. When thestraight across MR sensor reads this curved data there is progressivesignal loss from the center of the data track toward the outerextremities of the data track.

All merged magnetic heads have a separation between the read and writegaps. This separation causes misregistration between the read and writegaps when the magnetic head is located at outer tracks on the magneticdisk. In the magnetic disk drive, an actuator swings the magnetic headacross the rotating disk to various circular tracks on the disk. At theinnermost track the read and write gaps are substantially aligned withone another and there is substantially no misregistration. At theinner-most track the read gap follows within the track written by thewrite gap. However, when the actuator swings the magnetic head to theoutermost track the read and write gaps are misaligned with respect tothe track. If the write gap is within the track being written the readgap may be partially in the track and partially in an adjacent track.The misregistration increases with an increase in the separation betweenthe read and write gaps. In magnetic heads where the write head isconstructed before the read head the profile of the insulation stack ofthe write head raises the height of the first shield layer of the readhead. It would be desirable if this profile could be reduced so that theread and write gaps are closer together.

Still another problem with prior art magnetic heads is that heating ofhigh magnetic moment pole tips risks damage to the read sensor of theread head. A high magnetic material is Ni₄₅Fe₅₅ as compared to Ni₈₀Fe₂₀.Pole tips constructed of high magnetic material are desirable becausethey will conduct higher flux density without saturating. A stillfurther problem with prior art magnetic heads is the risk of shorting oflead layers in the read head through the first read gap layer to thefirst shield layer. The first and second read gap layers are purposelyvery thin so as to narrow the read gap and increase linear bit densityreading capability. Pinholes are more likely at steps in the first readgap layer than in flat portions of the first read gap layer. It isdesirable that the partially completed magnetic head be planarizedbefore the first read gap layer is constructed so as to reduce thechance of pinholes. The lack of planarity can cause still anotherproblem in the construction of one or more coil layers. If there is astep, such as at a side edge of the first pole piece layer, this willcause reflective notching in adjacent portions of a photoresist layeremployed to construct the coil layer.

SUMMARY OF THE INVENTION

The advantages of the present invention are as follows: (1)substantially eliminate reflective notching and increase resolution of aphotoresist pattern for constructing a pole tip that defines the trackwidth of the head, (2) eliminate write gap curvature, (3) lower theinsulation stack so that the read and write gaps are closer together,(4) planarize the construction of the partially completed head atvarious steps so that frame plating of metallic layers is more accurate,(5) high temperature construction of high magnetic moment pole tipswithout risking damage to the read sensor, (6) construction of a firstread gap layer on a planarized first shield layer so as to minimizeshorting of the lead layers to the first shield layer and (7) eliminatereflective notching of a photoresist pattern for constructing a coillayer.

In the present invention the write head of the merged magnetic head isconstructed before the read head. In one embodiment a first pole piecelayer is formed on a wafer with front and back upstanding components toform a recess between the components in a yoke region of the head. Aninsulation material, such as alumina, is deposited over the entirewafer. The wafer is then lapped until tops of the front and backcomponents are exposed leaving a bed of flat alumina therebetween, aswell as flat alumina portions adjacent side edges of the first polepiece layer. A first coil can then be frame plated on the flat aluminaportions with high resolution. The front and back components are thenbuilt up higher by frame plating followed by deposition of alumina andlapping to planarize the construction. A second coil may then be formedon the planar alumina surface.

A highly defined front component, which comprises the first pole tip,may then be frame plated on the flat alumina layer with substantially noreflective notching along with a back component which comprises a backgap. Alumina may then be deposited and lapped until top surfaces of thepole tip and the back gap are exposed. After deposition of a gap layer aflat second pole piece/first shield layer is frame plated followed bydeposition of another alumina layer and lapping until the partiallycompleted head is planar. Then a first read gap layer, read sensor,first and second lead layers and a second read gap layer are formed. Thefront components, other than the first pole tip, can be at or recessedfrom the ABS. Further, the first pole tip may be constructed before thesecond coil layer or on a flat alumina layer after forming the secondcoil layer.

With the present invention the insulation stack can be recessed withrespect to the write gap so that the profile of the insulation stackdoes not contribute to the separation between the read and write gaps.Since the read head is constructed after the write head, hightemperatures can be employed in the construction of a high magneticmoment first pole tip without damaging the read sensor. Since thepartially completed head is planarized before construction of a coillayer a more highly defined coil layer can be constructed. Anotherembodiment of the invention is a single coil magnetic head constructedsimilarly to that described for the double coil magnetic head.

An object of the present invention is to substantially eliminatereflective notching and increase resolution of a photoresist pattern forconstructing a pole tip that defines the track width of a write headbefore read head constructed merged magnetic head.

Another object is to eliminate write gap curvature.

A further object is to lower an insulation stack so that the read andwrite gaps are closer together.

Yet another object is to planarize the construction of a partiallycompleted magnetic head at various steps so that frame plating ofmetallic layers is more accurate.

Still another object is to employ high temperature construction of highmagnetic moment pole tips without risking damage to a read sensor.

Still a further object is to construct a first read gap layer withoutsteps so as to minimize shorting of first and second lead layers to afirst shield layer.

Still another object is to eliminate reflective notching of aphotoresist pattern for constructing a coil layer.

Other objects and attendant advantages of the invention will becomeapparent upon reading the following description taken together with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a planar view of an exemplary magnetic disk drive;

FIG. 2 is an end view of a slider with a magnetic head of the disk driveas seen in plane 2—2;

FIG. 3 is an elevation view of the magnetic disk drive wherein multipledisks and magnetic heads are employed;

FIG. 4 is an isometric illustration of an exemplary suspension systemfor supporting the slider and magnetic head;

FIG. 5 is an ABS view of the magnetic head taken along plane 5—5 of FIG.2;

FIG. 6 is a partial view of the slider and a prior art magnetic head asseen in plane 6—6 of FIG. 2;

FIG. 7 is a partial ABS view of the slider taken along plane 7—7 of FIG.6 to show the read and write elements of the prior art magnetic head;

FIG. 8 is a view taken along plane 8—8 of FIG. 6 with all material abovethe second pole piece removed;

FIG. 9 is an enlarged front portion of the prior art magnetic head ofFIG. 6 to show various details thereof;

FIG. 10 is the same as FIG. 9 except a photo-patterning step isillustrated for constructing the second pole tip of the magnetic head;

FIG. 11 is a view taken along plane 11—11 of FIG. 9;

FIG. 12 is a view taken along plane 12—12 of FIG. 10;

FIG. 13 is an isometric illustration of FIG. 10 without the P2photoresist;

FIG. 14 is an ABS view of a prior art merged MR head before notching ofthe first pole piece;

FIG. 15 is an ABS view of the merged MR head shown in FIG. 14 after ionmilling to form the first pole piece with notches adjacent the secondpole tip;

FIG. 16 is an isometric illustration of an embodiment of the presentinvention which has a double coil and a single first pole tip (pole tipdesign) at an air bearing surface;

FIG. 17 is an isometric illustration of the first pole piece and firstpole tip of the pole tip design shown in FIG. 16;

FIG. 18 is a longitudinal cross-section through the pole tip designemploying a double coil;

FIG. 19 is a longitudinal cross-sectional view of another embodiment ofthe pole tip design employing a single coil;

FIG. 20 is a schematic ABS illustration of an embodiment of the pole tipdesign;

FIG. 21 is a schematic ABS illustration of another embodiment of thepole tip design;

FIG. 22 is an isometric illustration of another embodiment of themagnetic head employing a double coil and top and bottom first pole tipswhich is referred to as a lip design;

FIG. 23 is an isometric illustration of the first pole piece of theembodiment shown in FIG. 22 showing a bottom first pole tip which lookslike a lip and a top first pole tip which is a pedestal;

FIG. 24 is a longitudinal cross-sectional view through the embodimentshown in FIG. 22;

FIG. 25 is a longitudinal cross-sectional view through anotherembodiment of the lip design showing a single coil layer;

FIG. 26 is an ABS illustration of one embodiment of the lip design;

FIG. 27 is an ABS illustration of another embodiment of the lip design;

FIG. 28 is an ABS illustration of a further embodiment of the lipdesign;

FIG. 29A is a longitudinal cross-sectional view of a first step ofplating a bottom layer portion of a first pole piece on a wafer;

FIG. 29B is the same as FIG. 29A except front and back components of thefirst pole piece have been formed;

FIG. 29C is the same as FIG. 29B except alumina is deposited on thewafer;

FIG. 29D is an ABS illustration taken along FIG. 29D—29D of FIG. 29C;

FIG. 29E is the same as FIG. 29C except the wafer has been lapped sothat all surfaces are flush with respect to one another;

FIG. 29F is an ABS view taken along plane 29F—29F of FIG. 29E;

FIG. 29G is the same as FIG. 29E except a first coil layer has beenframe plated on the wafer;

FIG. 29H is the same as FIG. 29G except front and back components of thefirst pole piece have been frame plated;

FIG. 29I is the same as FIG. 29H except alumina has been deposited onthe wafer;

FIG. 29J is an ABS illustration taken along plane 29J—29J of FIG. 29I;

FIG. 29K is the same as FIG. 29I except the wafer has been lapped untilall surfaces are flush with respect to one another;

FIG. 29L is an ABS view taken along plane 29L—29L of FIG. 29K;

FIG. 29M is the same as 29K except a seedlayer has been deposited;

FIG. 29N is the same as FIG. 29M except a second coil layer has beenframe plated;

FIG. 29O is the same as FIG. 29N except a photoresist pattern has beenformed;

FIG. 29P is a view taken along plane 29P—29P of FIG. 29O;

FIG. 29Q is the same as FIG. 29O except a first pole tip and a back gapportion have been frame plated;

FIG. 29R is a view taken along plane 29R—29R of FIG. 29Q;

FIG. 29S is the same as FIG. 29Q except the photoresist pattern has beenremoved;

FIG. 28T is an ABS view taken along plane 29T—29T of FIG. 29S;

FIG. 29U is the same as FIG. 29S except an alumina layer has beendeposited;

FIG. 29V is an ABS view taken along plane 29V—29V of FIG. 29U;

FIG. 29W is the same as FIG. 29U except the wafer has been lapped untilall surfaces are flush with respect to one another;

FIG. 29X is a view taken along plane 29X—29X of FIG. 29W;

FIG. 29Y is the same as FIG. 29W except a write gap layer has beendeposited;

FIG. 29Z is an ABS view taken along plane 29Z—29Z of FIG. 29Y;

FIG. 29AA is the same as FIG. 29Y except a second pole piece/firstshield layer has been frame plated;

FIG. 29AB is an ABS view taken along plane 29AB—29AB of FIG. 29AA;

FIG. 29AC is the same as FIG. 29AA except a layer of alumina has beendeposited on the wafer;

FIG. 29AD is a view taken along plane 29AD—29AD of FIG. 29AC;

FIG. 29AE is the same as FIG. 29AC except the wafer has been lappeduntil all surfaces are flush with respect to one another;

FIG. 29AF is a view taken along plane 29AF—29AF of FIG. 29AE;

FIG. 29AG is the same as FIG. 29AE except a first read gap, a readsensor, first and second lead layers, a second read gap and a secondshield layer have been formed; and

FIG. 29AH is an ABS view taken along plane 29AH—29AH of FIG. 29AG;

FIG. 30 is a block diagram of another method of the invention;

FIG. 31 is a block diagram of a further method of the invention;

FIG. 32 is a block diagram of yet another method of the invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Magnetic Disk Drive

Referring now to the drawings wherein like reference numerals designatelike or similar parts throughout the several views there is illustratedin FIGS. 1-3 a magnetic disk drive 30. The drive 30 includes a spindle32 that supports and rotates a magnetic disk 34. The spindle 32 isrotated by a motor 36 that is controlled by a motor controller 38. Acombined read and write magnetic head 40 is mounted on a slider 42 thatis supported by a suspension 44 and actuator arm 46. A plurality ofdisks, sliders and suspensions may be employed in a large capacitydirect access storage device (DASD) as shown in FIG. 3. The suspension44 and actuator arm 46 position the slider 42 so that the magnetic head40 is in a transducing relationship with a surface of the magnetic disk34. When the disk 34 is rotated by the motor 36 the slider is supportedon a thin (typically, 0.05 μm) cushion of air (air bearing) between thesurface of the disk 34 and the air bearing surface (ABS) 48. Themagnetic head 40 may then be employed for writing information tomultiple circular tracks on the surface of the disk 34, as well as forreading information therefrom. Processing circuitry 50 exchangessignals, representing such information, with the head 40, provides motordrive signals for rotating the magnetic disk 34, and provides controlsignals for moving the slider to various tracks. In FIG. 4 the slider 42is shown mounted to the suspension 44. The components describedhereinabove may be mounted on a frame 54, as shown in FIG. 3.

FIG. 5 is an ABS view of the slider 42 and the magnetic head 40. Theslider has a center rail 56 that supports the magnetic head 40, and siderails 58 and 60. The rails 56, 58 and 60 extend from a cross rail 62.With respect to rotation of the magnetic disk 34, the cross rail 62 isat a leading edge 64 of the slider and the magnetic head 40 is at atrailing edge 66 of the slider.

Prior Art Merged MR Head

FIG. 6 is a side cross-sectional elevation view of the merged MR head 40which has a prior art write head portion 70 and a read head portion 72,the read head portion employing an MR sensor 74. FIG. 7 is an ABS viewof FIG. 6. The sensor 74 is located between first and second gap layers76 and 78 and the gap layers are located between first and second shieldlayers 80 and 82. In response to external magnetic fields, theresistance of the sensor 74 changes. A sense current I_(s) conductedthrough the sensor causes these resistance changes to be manifested aspotential changes. These potential changes are then processed asreadback signals by the processing circuitry 50 shown in FIG. 3.

The prior art write head portion of the merged MR head includes a coillayer 84 located between first and second insulation layers 86 and 88. Athird insulation layer 90 may be employed for planarizing the head toeliminate ripples in the second insulation layer caused by the coillayer 84. The first, second and third insulation layers are referred toin the art as an “insulation stack”. The coil layer 84 and the first,second and third insulation layers 86, 88 and 90 are located betweenfirst and second pole piece layers 92 and 94. The first and second polepiece layers 92 and 94 are magnetically coupled at a back gap 96 andhave first and second pole tips 98 and 100 which are separated by awrite gap layer 102 at the ABS. As shown in FIGS. 2 and 4, first andsecond solder connections 104 and 106 connect leads from the sensor 74to leads 112 and 114 on the suspension 44 and third and fourth solderconnections 116 and 118 connect leads 120 and 122 from the coil 84 (seeFIG. 8) to leads 124 and 126 on the suspension. A wear layer 128 may beemployed for protecting the sensitive elements of the magnetic head, asshown in FIGS. 2, 4, 6 and 7. It should be noted that the merged MR head40 employs a single layer 82/92 to serve a double function as a secondshield layer for the read head and as a first pole piece for the writehead. A piggyback MR head employs two separate layers for thesefunctions.

As shown in FIG. 9, the second pole piece layer 94 has a pole tip regionand a yoke region, the merging of these components being defined by aflare point 130 which is the location where the second pole piece layer74 begins to widen as it recesses in the head. The second pole tipregion extends from the ABS to the flare point 130, and the yoke regionextends from the flare point 130 to the back gap 96 (see FIG. 6). InFIG. 12 are shown the pole tip region, the yoke region and the flarepoint 130 as defined by a photoresist mask (P2 frame).

The location of the flare point 130, shown in FIGS. 9, 12 and 13, is animportant design parameter of the write head. The further the flarepoint is recessed into the head, the longer the pole tip 100, whichincreases magnetic inductance and the likelihood that the pole tip 100will saturate in response to flux from the coil layer 84. In the past ithas been difficult to locate the flare point closer to the ABS than 10μm because of a fabrication problem in making the second pole tip.

Another important design parameter in making the write head is thelocation of a zero throat height (ZTH), which is where the first andsecond pole piece layers 92 and 94 first separate from one anotherbehind the ABS. It is important to locate the ZTH as close as possibleto the ABS (typically within about 1 μm) in order to reduce flux lossbetween the pole pieces before the fields reach the gap layer 102 at theABS. In the prior art, locating the ZTH close to the ABS contributed tothe aforementioned problem of fabricating a well-defined second pole tip100.

FIG. 10 shows the prior art head of FIG. 9 during the step ofconstructing the second pole piece 94 (see FIG. 9). In FIG. 10 thefirst, second and third insulation layers 86, 88 and 90 are shown withsloping surfaces 132, 134 and 136 respectively, which terminate atapexes 138, 139 and 140 respectively. As stated hereinabove, the first,second and third insulation layers are hard-baked photoresist whichresults in the sloping surfaces 132, 134 and 136 being highly reflectiveto light. All of the sloping surfaces 132, 134 and 136 face the pole tipregion where the second pole tip 100 of the second pole piece 94 is tobe formed. As shown in FIG. 10, the second pole piece is formed with aphotoresist layer 141 that is spun on top of the partially completedhead. The height of the photoresist layer may be as much as 12 μm thickin the pole tip region and is typically approximately 4.5 μm thick abovethe third insulation layer 90. Since the flare point 130 of the secondpole piece 94 (shown in FIGS. 9, 12 and 13) is located on the slopingsurfaces of the insulation layers, light directed through a secondpole-shaped opening (not shown) in a mask 142 will be reflected from thesloping surfaces forward toward the ABS into areas of the photoresistlayer 141 adjacent the pole tip region. This causes the pole tip regionto be wider than the opening in the mask 142. This is referred to as“reflective notching” and is illustrated in FIG. 12.

The photoresist pattern for the second pole piece is shown in FIG. 12 at94′ which comprises the second pole tip pattern 100′ and the second polepiece yoke pattern 103′. This is referred to as the “P2 frame”.Reflective notching of the photoresist layer 141 (see FIG. 10) by lightreflected at an angle of incidence from the sloping layers of theinsulation layers is shown at 144 and 146 in FIG. 12. When light ray Ais directed downwardly during the photo-imaging step of the photoresist,it is reflected at an angle of incidence from the insulation stack intothe pole tip region without causing any reflective notching of thesecond pole tip. However, light ray B from the photo-imaging process isreflected from the sloping surfaces of the insulation layers behind theflare point 130 at an angle of incidence into the photoresist 141 in aside region outside the intended pole tip pattern 100′. It is lightreflection B and similar light reflections that cause the reflectivenotching shown in FIG. 12.

When the second pole piece 94 is plated and the photoresist layer 141 isremoved the head is complete, as shown in FIG. 9. However, the pole tip100 is poorly formed, exhibiting irregular side walls 148 and 150, asshown in FIG. 11. Furthermore, photoresist notching results in a secondpole tip 100 that has wider areas at the upper pole tip region than atthe base of the pole tip (adjacent the write gap). If the irregularsecond pole tip 100 is used as a milling mask to notch the first poletip 98, the wider regions of the second pole tip shadows the millingbeam. Thus, the milling process is less effective at removing the firstpole tip material directly beneath the side walls of the second poletip. This results in a poorly formed P1 notched write head structure dueto incomplete notching of the first pole piece 72. These poorly formedpole tips result in side writing of adjacent tracks.

FIG. 14 is an ABS view of a prior art merged magnetic head 150 after aP2 seedlayer (not shown) has been removed by ion milling. It can be seenthat the ion milling has slightly notched the gap layer 102 at 154 and156. One method of notching the first pole piece layer 82/92 in theprior art is to ion mill through the gap layer into the first pole piecelayer, as shown in FIG. 15. This notches the first pole piece layer at159 and 160. Notching of the first pole piece layer 82/92 is desirablesince it minimizes side writing between the second pole tip 100 and thefirst pole piece 82/92. Unfortunately, the process shown in FIG. 15results in consumption of a top surface 159 of the second pole tip 100,as shown by the phantom lines in FIG. 15. Since ion milling is typicallyperformed at an angle to a normal to the thin film layers, as shown inFIG. 15, the second pole tip 158 shadows the milling of the notching at159 and 160 approximately 50% of the time while the workpiece isrotated. Consequently, the first pole piece 82/92 is overmilled inlocations 164 and 166 which extend in the field remote from the notches159 and 160 respectively. This causes the first pole piece 82/92 to havedownwardly sloping top surfaces 164 and 166, as shown in FIG. 15, whichundesirably reduces the thickness of the first pole piece 82/92 in thefield. This can potentially expose sensitive elements beneath the firstpole piece 82/92 rendering the head inoperative. The gap layer 102 millsmore slowly than the Permalloy (NiFe) of the first and second polepieces which results in more rapid ion milling of the top 159 of thesecond pole tip 100 and the fields 164 and 166 of the first pole piece82/92 than the gap layer 102.

It can be seen from FIG. 15 that the beginning thickness of the secondpole tip layer 100 has to be thicker than the final height of the secondpole tip layer at 159 in order to compensate for the top portion of thesecond pole tip layer consumed by ion milling. This then requires thephotoresist mask to be thicker which increases the aforementionedproblem of additional light scattering during the light photo-imagingstep as the photoresist layer increases in depth. This means that thesecond pole tip cannot be constructed as narrow because of loss ofdefinition during the photoresist patterning. FIG. 15 also shows thewrite gap 102 slightly curved due to the profile of the MR sensor beingreplicated through the second shield first pole tip layer 82/92 to thegap layer 102. Accordingly, it can now be seen that the prior art mergedMR head suffers from the disadvantages of reflective notching of thesecond pole tip, loss of a top portion of the second pole tip uponnotching the first pole piece and write gap curvature. These problemsare overcome by the inverted merged MR head described hereinbelow.

Another problem with the prior art head in FIGS. 14 and 15 is that thewrite gap 102 has a curvature due to replication of the profile of theMR sensor by the second gap layer 78 and the second shield/first polepiece layer 82/92. As discussed hereinabove, this causes information tobe written in a curve across a track which is inaccurately read by thestraight MR sensor 74.

The Invention

FIGS. 16 and 18 show a first embodiment 200 of the present inventionwherein a read head portion of a merged magnetic head is constructed ontop of a write head portion. The write head includes first and secondpole pieces 202 and 204 (P1 and P2), respectively, which are separatedby a gap layer 206 at the ABS to form a write gap therebetween and areconnected at a back gap 208. An insulation stack 210 is locatedvertically between the first and second pole pieces and horizontallybetween the air bearing surface (ABS) and the back gap 208. First andsecond coil layers 212 and 214 may be embedded in the insulation stackwith the first coil 212 being separated from the first pole piece 202 bya first insulation layer 216, the first and second coil layers beingseparated from one another by a second insulation layer 218 and thesecond coil layer 214 being insulated from the second pole piece 204 bya third insulation layer 220. During construction of the write headportion, the top surfaces of each of these insulation layers areplanarized with respect to top surfaces of front and rear components ofthe first pole piece, which will be discussed in more detail hereinafterunder the method of construction.

The first pole piece includes a first pole piece layer 222 which has anintermediate component 224 between front and rear components 226 and228. Each of these components has top and bottom surfaces which aresubstantially flat and define a planar surface. A first pole tip 230 islocated on the front component of the first pole piece layer and has awidth at the ABS which defines the track width (TW) of the write head,as shown in FIGS. 20 and 21. The first pole tip also has a back wall 232that defines a zero throat height (ZTH) of the write head where thefirst and second pole pieces first commence to separate from one anotherafter the ABS. The flare point of the head, which is where the firstpole piece layer 222 first commences to widen after the ABS, is shown at234. The pole tip region of the head is defined between the ABS and theflare point. As shown in FIG. 18, the write head portion has a yokeregion which is located between the pole tip region and the back gapregion. The first pole tip 230 is the only pole tip of the first polepiece and is connected to the front component 226. Accordingly, the headshown in FIGS. 16-21 is referred to as a pole tip design since there isno bottom first pole tip. This is clearly shown in FIG. 17 where onlythe front portion of the bottom pole piece 202 is illustrated. The firstpole tip 230 has a substantially uniform width from its top to itsbottom which defines the track width of the head. The first pole tip canbe easily constructed by frame plating on a planar surface, which willbe discussed in more detail hereinafter, and has a back wall 232 thatdefines the zero throat height with great accuracy. The frame plating ofthe first pole tip on a planar surface also eliminates reflectivenotching and promotes high resolution of the side walls of the firstpole tip. The first pole tip 230 can be a high moment magnetic material,such as Ni₄₅Fe₅₅, since it is constructed separately from the remainderof the first pole piece 202. This high moment material can be annealedat a high temperature without damage of a read sensor, which is to bedescribed hereinafter. Since the insulation layers of the insulationstack 208 are planarized at each step, the coil layers 212 and 214 canbe frame plated without reflective notching with high resolution oftheir side walls.

After planarizing the top insulation layer 220 with the top of the firstpole tip 230 the write gap layer 206 is deposited, which extends fromthe ABS to the back gap 208. Accordingly, a second pole piece/firstshield layer 204 (P2/S1) can be a substantially flat layer. This enablesthe following layers, namely the first and second read gap layers 238and 240, a read sensor 242 and first and second lead layers 244 and 245located between the first and second read gap layers and a second shieldlayer 246 (S2) to be planar. This is especially important for the firstread gap layer 238 since steps in the second pole piece/first shieldlayer 204 risk pinholes in the first read gap layer, which allow thefirst and second lead layers 244 and 245 to short to the second polepiece/first shield layer 204.

The preferred material for the insulation layers of the insulation stack210 and the extensions of these layers beyond side edges of the firstpole piece layer 202 is alumina or silicon dioxide in lieu of bakedphotoresist. The extensions of these layers beyond the side edges 247and 248 of the first pole piece layer 202, which are shown hereinafterin the method of making, provide flat surfaces for the construction ofthe first and second coil layers 212 and 214. The construction of thefirst insulation layer 216 (see FIG. 18) fills in the steps caused bythe first and second side edges 247 and 248 of the first pole piecelayer 202 so as to promote planarization.

Another embodiment 250 of the pole tip design is shown in FIG. 19 whichemploys a single coil layer 252 in lieu of a double coil layer. As inthe double coil layer embodiment, the first pole piece 254 includes anintermediate component 256 between front and rear components, the frontcomponent being shown at 258. The front component 258 extends to the ABSand the first pole tip 262 is constructed thereon. The front component258 and the first pole tip 262 have the same width which defines thetrack width (TW) of the head. The insulation stack 264 has first, secondand third insulation layers 266, 268 and 270 with the coil layer 252 onthe first insulation layer 266. The second insulation layer 268 isplanarized with the top surface 270 of the front component so that thefirst pole tip 262 can be constructed with a photoresist frame on a flatsurface.

FIG. 20 is an ABS illustration of either of the embodiments shown inFIG. 18 or 19. FIG. 21 is an alternative embodiment wherein the secondpole piece 204 has a bottom second pole tip 272 (P2B) and a top secondpole tip 274 (P2T). The bottom second pole tip 272 has substantially thesame width as the first pole tip 230 and is separated therefrom by thewrite gap layer 206. This embodiment is referred to in the art as beingnotched since the bottom second pole tip 272 is the same width as thefirst pole tip 230. The purpose of the notched configuration is toslightly increase side writing between the pole pieces which has theeffect of writing a guard band of noise on each side of the writtentrack so that when the track is read by the read head a slightmisregistration will not cause the read head to read data on an adjacenttrack. In the construction of the embodiment shown in FIG. 21, thebottom second pole tip 272 can be frame plated after electroplating thewrite gap of NiP or Pd or Ir followed by the deposition of alumina andlapping to make a planar surface for the construction of the top secondpole tip.

Another embodiment 300 of the merged magnetic head is shown in FIGS.22-28. This embodiment differs from the first embodiment in that thefront component 302 of the first pole piece 301 has a width at the ABSthat is wider than the first pole tip 304. Accordingly, the frontcomponent 302 forms a bottom first pole tip 306 (P1B) and the pole tipthereon is a top first pole tip 304 (P1T). The top first pole tip 304defines the track width (TW) of the head, as shown in FIGS. 26-28.Except for the front component 302 defining a bottom first pole tip 306,the double coil head shown in FIGS. 22 and 24 is the same as the firstembodiment shown in FIGS. 16 and 18. FIG. 23 shows more clearly thefront portion 302 of the first pole piece 301 wherein the wide expanseof the bottom first pole tip 306 at the ABS appears as a lip.Accordingly, the embodiment 300 is referred to hereinafter as the lipdesign. The top first pole tip 304 is constructed directly on the topsurface of the bottom first pole tip 306 after the top surface 308 ofthe bottom first pole tip 306 is planarized with the top surface of thesecond insulation layer 312. The single coil lip design, shown in FIG.25, is the same as the single coil pole tip design shown in FIG. 19,except the front component 320 of the first pole piece forms a bottomfirst pole tip 322 which is wider than the top first pole tip 324. Itshould be noted that the lip design in FIGS. 22, 24 and 25 does not havea flare point since the bottom first pole tip 322 is the same width asthe first pole piece 324 from the ABS to the back gap 326. As shown inFIG. 22, insulation of the insulation stack 310 extends beyond sideedges 347 and 348 of the first pole piece to planarize the wafer forconstruction of the coil layers 312 and 314.

FIGS. 26-28 illustrate various configurations for the lip design at theABS. The illustration in FIG. 26 is representative of the air bearingsurfaces of the heads shown in FIGS. 22, 24 and 25. FIG. 27 is amodification of the illustration shown in FIG. 26 in that the secondpole piece layer 360 has first and second upwardly inclined portions 362and 364 which are connected to elevated first and second flat portions366 and 368. The purpose of this construction is to further separate thebottom outside corners 370 and 372 of the second pole piece layer fromthe wide expanse of the bottom first pole tip 374. Since high fluxdensities are concentrated in these corners, this extra distanceminimizes flux leakage between the second pole piece layer 360 and thebottom first pole tip 374. In FIG. 28, the second pole piece 376 isprovided with top and bottom second pole tips 378 and 380 in a notchedconfiguration so as to promote a slight amount of side writing, asexplained hereinabove with regard to FIG. 21.

Method of Construction

An exemplary method of construction of the merged magnetic head 300,shown in FIGS. 22 and 24, is shown in FIGS. 29A-29AH. In FIG. 29A abottom flat layer portion 400 of a first pole piece is frame plated on awafer 401. In FIG., 29B a first front component 402 and a first rearcomponent 404 are frame plated on the layer 400 in a spaced relationshipso as to define a recess 406 therebetween. In FIG. 29C alumina issputter deposited over the entire wafer covering all components of thefirst portion of the first pole piece layer. FIG. 29D is an ABSillustration of FIG. 29C showing how the alumina fills in the steps atfirst and second side edges 408 and 410 of the first front component402. In FIG. 29E the wafer is chemically mechanically polished (CMP),which causes top surfaces 412, 414 and 416 of the alumina layer and topsurfaces 418 and 420 of the first front component and the first rearcomponent to be flush with respect to one another. This provides a firstinsulation layer 422 within the recess and insulation layers 424 and 426in the field beyond front and rear edges 428 and 430 of the bottom layerportion of the first pole piece layer. FIG. 29F is an ABS view of FIG.29E showing the alumina to have first and second layers 432 and 434adjacent first and second side edges 436 and 438 of the bottom portionof the first pole piece so as to planarize the wafer in the field beyondthe partially completed magnetic head.

In FIG. 29G a first coil layer 440 is frame plated on the firstinsulation layer employing a photoresist frame (not shown), which isplanarized across the wafer. In FIG. 29H a second front component 442and a second rear component 444 are frame plated on the first frontcomponent and the first rear component, respectively, thereby raisingthe front and back ends of the partially completed first pole piece toform a second recess 450 above the first coil layer 440. The secondfront component may have a step 452 for facilitating placement of asecond coil, which will be described hereinafter. If desired, the orderof the steps in FIGS. 29G and 29H can be reversed which will bediscussed in more detail hereinafter. In FIG. 29I alumina is depositedover the entire wafer covering the entire partially completed head. FIG.29J is an ABS illustration of the partially completed head shown in FIG.29I. In FIG. 29K the wafer is CMP causing the deposited alumina to forma second insulation layer 454 in an intermediate region of the partiallycompleted head and layer portions 456 and 458 forward and rearward ofthe head to planarize the entire wafer. FIG. 29L is an ABS illustrationof FIG. 29K.

In FIG. 29M a seedlayer 460 is sputter deposited over the entire waferin preparation for electroplating a second coil. In FIG. 29N a secondcoil layer 462 has been frame plated on the second insulation layer 454.In FIG. 29O a photoresist layer 464 has been spun on the wafer andphoto-patterned to provide openings 466 and 467 for constructing the topfirst pole tip and a back gap portion of the first pole piece layer. Theseedlayer 460 for the coil layer 462 is removed and a seedlayer 465 isdeposited for constructing the top first pole tip. The photoresist layer464 can be significantly thinner since it does not have to accommodatethe profile of an insulation stack. The thinner resist allows moreefficient penetration of light during the light exposure step so as topromote high resolution of the side walls 468 and 469 of the opening inthe resist and the side walls of the top first pole tip which is to beplated therein, as shown in FIG. 29P. In FIG. 29Q the top first pole tip470 and the back gap portion 472 are plated through openings in thephotoresist layer. FIG. 29R is an ABS illustration of FIG. 29Q. In FIG.29S the photoresist is removed and any remaining seedlayer is alsoremoved by ion milling. FIG. 29T is an ABS illustration of FIG. 29S.Constructing the top first pole tip by the above-described photoresistpatterning scheme results in a superior first pole tip 470 which can besubmicron with high resolution.

In FIG. 29U an alumina layer 474 is deposited on the entire wafer. FIG.29V is an ABS illustration of FIG. 29U. In FIG. 29W the entire wafer isCMP causing the alumina to form a third insulation layer 476 above thesecond coil layer 462 with front and rear layer portions 478 and 480which are flush with top surfaces of the top first pole tip 470 and theback gap region 472. FIG. 29X is an ABS illustration of FIG. 29W. InFIG. 29Y a write gap layer 482 is sputter deposited, which is preferablya full film layer over the entire wafer. This will maintainplanarization of the partially completed head with respect to the restof the wafer. FIG. 29Z is an ABS illustration of FIG. 29Y. In FIG. 29AAa second pole piece/first shield layer 484 (P2/S1) is frame plated onthe gap layer 482 and is flat because of the flatness of the gap layer.FIG. 29AB is an ABS illustration of FIG. 29AA.

In FIG. 29AC alumina 485 is once again sputter deposited over the entirewafer. FIG. 29AD is an ABS illustration of FIG. 29AC. In FIG. 29AE theentire wafer is CMP to ensure planarization of the second polepiece/first shield layer 484 for forming a first read gap layer thereon.FIG. 29AF is an ABS illustration of FIG. 29AE. Next, the read gap layer486, read sensor 488 and first and second leads (not shown) are frameplated on the first read gap layer followed by sputter deposition of asecond read gap layer 490 and a second shield layer 492. FIG. 29AH is anABS illustration of FIG. 29AG. The wafer is now ready for an overcoatlayer (not shown) which essentially completes the construction of themerged magnetic head.

As stated hereinabove, the steps in regard to the construction of thesecond coil layer and the first pole tip, shown in FIGS. 29N and 29Q,may be reversed in their order. When these steps are reversed the methodwould be as shown in FIG. 30. The seedlayer is still deposited as shownin FIG. 29M. The next step would be to form the first pole tip 470 andback gap 472 (FIG. 29Q). Next, the second coil 462 would be formed (FIG.29N) followed by deposition of the alumina layer over the entire wafer(FIG. 29V). The wafer is then CMP and the write gap layer 482 is formed,as shown in FIG. 29Y.

FIG. 31 illustrates still another modification of the method. Aseedlayer is deposited on the second insulation layer above the firstcoil, as shown in FIG. 29M, followed by formation of the second coil(FIG. 29N). Next, front and rear components of the first pole piece areformed followed by deposition of alumina over the entire wafer. AfterCMP the wafer flat until the top surfaces of the front and rearcomponents are exposed, the first pole tip and back gap can then beformed on the front and rear components respectively. Next, an aluminalayer is deposited over the entire wafer followed by lapping. The writegap layer can then be deposited, as shown in FIG. 29Y. This modifiedmethod would enable construction of the first pole tip and the back gapon an entirely flat wafer without the presence of a coil layer.

FIG. 32 shows exemplary steps for the construction of the mergedmagnetic heads shown in FIGS. 19 and 25. The first step is to form abottom layer of a first pole piece, as shown in FIG. 29A, followed byforming front and rear components of the first pole piece, as shown inFIG. 29B. Next, alumina is deposited followed by CMP the wafer until thetop surfaces of the front and rear components are flush with the aluminalayer. A single coil layer is then formed followed by formation of thefirst pole tip and back gap. Alumina is then again deposited and thewafer lapped until the top surfaces of the first pole tip and the backgap are flush with the alumina layer. The write gap can then bedeposited, as shown in FIG. 29Y. The remainder of the steps forconstructing the read head would be as shown in FIGS. 29AA-29AH. Itshould be noted that the fifth and sixth steps in FIG. 32 could bereversed so that the first pole tip and back gap are formed before thecoil layer. Further, the method could be modified by forming secondfront and second rear components on the first front and first rearcomponents after construction of the coil layer followed by depositionof alumina and lapping to provide a flat surface for the construction ofthe first pole tip and back gap.

The construction of the pole tip design shown in FIGS. 16-21 is similarto the method described hereinabove, except the photoresist patterningfor the front portions of the first pole piece layer differ slightly inorder to obtain the configurations shown. The construction of the singlelayer embodiments shown in FIGS. 19 and 25 would employ the methoddescribed hereinabove except the construction of the second coil layeris omitted.

In some embodiments it may be desirable to employ a high magnetic momentfor the first pole tip which may be Ni₄₅Fe₅₅. It should be noted fromFIGS. 29O-29T that a different material can be employed for the topfirst pole tip than employed for the remainder of the first pole piece.A top first pole tip constructed of Ni₄₅Fe₅₅ can be annealed to improveits properties without damaging the read sensor since it has not yetbeen constructed. The read sensor can be either a magnetoresistive (MR)sensor or a spin valve sensor which are both well known in the art. Inlieu of alumina (Al₂O₃) silicon dioxide (SiO₂) may be employed. Aluminaor silicon dioxide have greater electrical insulating and thermalinsulating properties than hard baked photoresist. While it is preferredthat the write gap layer be alumina, it should be understood that it maybe a nonmagnetic material, such as copper, which is frame plated orsputter deposited. While frame plating is preferable for all of themetallic layers, it should be understood that these layers could besputter deposited employing bilayer photoresist techniques which arewell known in the art. The alumina layers or silicon dioxide layers arepreferably sputter deposited. The read gap layers are preferably aluminaand the read sensor is preferably constructed of Permalloy (Ni₈₀Fe₂₀).

Clearly, other embodiments and modifications of this invention willoccur readily to those of ordinary skill in the art in view of theseteachings. Therefore, this invention is to be limited only by thefollowing claims, which include all such embodiments and modificationswhen viewed in conjunction with the above specification and accompanyingdrawings.

I claim:
 1. A method of making a merged magnetic head that has an airbearing surface (ABS) and read and write head portions, the write headportion having pole tip, yoke and back gap regions comprising: makingthe write head as follows: forming first and second pole pieces, thefirst pole piece having a first pole tip and the second pole piecehaving a second pole tip; forming a gap layer; separating the pole tipsby the gap layer in the pole tip region and connecting the first andsecond pole pieces in the back gap region; forming an insulation stackwith a plurality of insulation layers; embedding at least one write coillayer in the insulation stack; locating the insulation stack between thefirst and second pole pieces in the yoke region; and making the firstpole tip with a width at the ABS that defines a track width of the writehead portion; making the read head portion as follows: forming a firstshield layer which is a common layer with said second pole piece;forming first and second read gap layers on the first shield layer;locating a read sensor between the first and second gap layers; andforming a second shield layer on the second read gap layer.
 2. Themethod as claimed in claim 1 including: forming the gap layer withsubstantially flat top and bottom surfaces that extend from the ABS tothe back gap; forming the common layer as a substantially flat layerwith top and bottom surfaces that extend from the ABS to the back gap;and forming each of the first and second read gap layers and the secondshield layer as substantially flat layers.
 3. The method as claimed inclaim 1 wherein the head has a top and a bottom with the read headportion being on top of the write head portion and having front and rearportions with the front portion being at the ABS and the back portionbeing at the back gap, the method further including: forming the firstpole tip with a top surface and a bottom with the top surface beingimmediately adjacent the gap layer and defining a top surface plane;forming the coil layer with substantially flat top and bottom surfacesthat define top and bottom surface planes; and locating the top surfaceplane of the coil layer below the top surface plane of the first poletip.
 4. The method as claimed in claim 3 including: forming the gaplayer with substantially flat top and bottom surfaces that extend fromthe ABS to the back gap; forming the common layer as a substantiallyflat layer with top and bottom surfaces that extend from the ABS to theback gap; and forming each of the first and second read gap layers andthe second shield layer as substantially flat layers.
 5. The method asclaimed in claim 1 including: forming the first pole piece with a firstpole piece layer; forming the first pole piece layer with anintermediate component between front and rear layer components with eachof the front and rear layer components having substantially flat top andbottom surfaces that define top and bottom surface planes; locating thetop surface plane of the front layer component higher than the topsurface plane of the intermediate layer component and the top surfaceplane of the first pole tip higher than the top surface plane of thefront layer component; the coil formed being the only coil in the head;and locating the top and bottom surface planes of the coil between thetop surface plane of the intermediate layer component and the topsurface plane of the first pole tip.
 6. The method as claimed in claim 5including: forming the gap layer with substantially flat top and bottomsurfaces that extend from the ABS to the back gap; forming the commonlayer as a substantially flat layer with top and bottom surfaces thatextend from the ABS to the back gap; and forming each of the first andsecond read gap layers and the second shield layer as substantially flatlayers.
 7. The method as claimed in claim 6 including: locating the topand bottom surface planes of the coil between the top surface plane ofthe intermediate layer component and the top surface plane of the frontlayer component.
 8. The method as claimed in claim 1 including: formingthe first pole piece with a first pole piece layer; forming the firstpole piece layer with an intermediate component between front and rearlayer components with each of the front and rear layer components havingsubstantially flat top and bottom surfaces that define top and bottomsurface planes; locating the top surface plane of the front layercomponent higher than the top surface plane of the intermediate layercomponent and the top surface plane of the first pole tip higher thanthe top surface plane of the front layer component; the coil layerformed being a first coil layer; forming a second coil layer; formingeach of the coil layers with substantially flat top and bottom surfacesthat define top and bottom surface planes; and locating the top andbottom surface planes of the first coil layer between the top surfaceplane of the intermediate layer component and the top surface plane ofthe front layer component and locating the top and bottom surface planesof the second coil layer between the top surface of the front layercomponent and the top of the first pole tip.
 9. The method as claimed inclaimed 8 including: forming the gap layer with substantially flat topand bottom surfaces that extend from the ABS to the back gap; formingthe common layer as a substantially flat layer with top and bottomsurfaces that extend from the ABS to the back gap; and forming each ofthe first and second read gap layers and the second shield layer assubstantially flat layers.
 10. The method as claimed in claim 1including: forming the first pole tip as the only first pole tip;forming each of the first and second pole tips with a front surface atthe ABS that has a width; and forming the width of the front surface ofthe second pole tip greater than the width of the front surface of thefirst pole tip.
 11. The method as claimed in claim 10 including: formingthe gap layer with substantially flat top and bottom surfaces thatextend from the ABS to the back gap; forming the common layer as asubstantially flat layer with top and bottom surfaces that extend fromthe ABS to the back gap; and forming each of the first and second readgap layers and the second shield layer as substantially flat layers. 12.The method as claimed in claim 11 including: forming the first polepiece with a first pole piece layer; forming the first pole piece layerwith an intermediate component between front and rear layer componentswith each of the front and rear layer components having substantiallyflat top and bottom surfaces that define top and bottom surface planes;locating the top surface plane of the front layer component higher thanthe top surface plane of the intermediate layer component and the topsurface plane of the first pole tip higher than the top surface plane ofthe front layer component; the coil formed being the only coil in thehead; and locating the top and bottom surface planes of the coil betweenthe top surface plane of the intermediate layer component and the topsurface plane of the first pole tip.
 13. The method as claimed in claim12 including: locating the top and bottom surface planes of the coilbetween the top surface plane of the intermediate layer component andthe top surface plane of the front layer component.
 14. The method asclaimed in claim 13 including: forming the front layer portion so thatit widens between the second pole tip and the coil layer.
 15. The methodas claimed in claim 11 including: the second pole tip formed being theonly second pole tip.
 16. The method as claimed in claim 15 including:forming the first pole piece with a first pole piece layer; forming thefirst pole piece layer with an intermediate component between front andrear layer components with each of the front and rear layer componentshaving substantially flat top and bottom surfaces that define top andbottom surface planes; locating the top surface plane of the front layercomponent higher than the top surface plane of the intermediate layercomponent and the top surface plane of the first pole tip higher thanthe top surface plane of the front layer component; the coil formedbeing the only coil in the head; locating the top and bottom surfaceplanes of the coil between the top surface plane of the intermediatelayer component and the top surface plane of the first pole tip; andforming the front layer portion so that it widens between the secondpole tip and the coil layer.
 17. The method as claimed in claim 15including: forming the first pole piece with a first pole piece layer;forming the first pole piece layer with an intermediate componentbetween front and rear layer components with each of the front and rearlayer components having substantially flat top and bottom surfaces thatdefine top and bottom surface planes; locating the top surface plane ofthe front layer component higher than the top surface plane of theintermediate layer component and the top surface plane of the first poletip higher than the top surface plane of the front layer component; thecoil layer formed being a first coil layer; forming a second coil layer;forming each of the coil layers with substantially flat top and bottomsurfaces that define top and bottom surface planes; locating the top andbottom surface planes of the first coil layer between the top surfaceplane of the intermediate layer component and the top surface plane ofthe front layer component and locating the top and bottom surface planesof the second coil layer between the top surface of the front layercomponent and the top of the first pole tip; and forming the front layerportion so that it widens between the second pole tip and the coillayer.
 18. The method as claimed in claim 11 including: the second poletip formed being a top second pole tip; forming a bottom second pole tipthat has a front surface at the ABS with a width substantially equal tothe width of the first pole tip; and forming the top second pole tipbeing on the bottom second pole tip with a width that is greater thanthe width of the bottom second pole tip.
 19. The method as claimed inclaim 18 including: forming the first pole piece with a first pole piecelayer; forming the first pole piece layer with an intermediate componentbetween front and rear layer components with each of the front and rearlayer components having substantially flat top and bottom surfaces thatdefine top and bottom surface planes; locating the top surface plane ofthe front layer component higher than the top surface plane of theintermediate layer component and the top surface plane of the first poletip higher than the top surface plane of the front layer component; thecoil formed being the only coil in the head; locating the top and bottomsurface planes of the coil between the top surface plane of theintermediate layer component and the top surface plane of the first poletip; and forming the front layer portion so that it widens between thesecond pole tip and the coil layer.
 20. The method as claimed in claim18 including: forming the first pole piece with a first pole piecelayer; forming the first pole piece layer with an intermediate componentbetween front and rear layer components with each of the front and rearlayer components having substantially flat top and bottom surfaces thatdefine top and bottom surface planes; locating the top surface plane ofthe front layer component higher than the top surface plane of theintermediate layer component and the top surface plane of the first poletip higher than the top surface plane of the front layer component; thecoil layer formed being a first coil layer; forming a second coil layer;forming each of the coil layers with substantially flat top and bottomsurfaces that define top and bottom surface planes; locating the top andbottom surface planes of the first coil layer between the top surfaceplane of the intermediate layer component and the top surface plane ofthe front layer component and locating the top and bottom surface planesof the second coil layer between the top surface of the front layercomponent and the top of the first pole tip; and forming the front layerportion so that it widens between the second pole tip and the coillayer.
 21. The method as claimed in claim 11 including: forming thefirst pole piece with a first pole piece layer; forming the first polepiece layer with an intermediate component between front and rear layercomponents with each of the front and rear layer components havingsubstantially flat top and bottom surfaces that define top and bottomsurface planes; locating the top surface plane of the front layercomponent higher than the top surface plane of the intermediate layercomponent and the top surface plane of the first pole tip higher thanthe top surfaces plane of the front layer component; the coil layerformed being a first coil layer; forming a second coil layer; formingeach of the coil layers with substantially flat top and bottom surfacesthat define top and bottom surface planes; and locating the top andbottom surface planes of the first coil layer between the top surfaceplane of the intermediate layer component and the top surface plane ofthe front layer component and locating the top and bottom surface planesof the second coil layer between the top surface of the front layercomponent and the top of the first pole tip.
 22. The method as claimedin claim 21 including: forming the front layer portion so that it widensbetween the second pole tip and the coil layer.
 23. The method asclaimed in claim 1 including: forming the first pole piece with a firstpole piece layer; forming the first pole piece layer with anintermediate component between front and rear layer components with eachof the front and rear layer components having substantially flat top andbottom surfaces that define top and bottom surface planes; locating thetop surface plane of the front layer component higher than the topsurface plane of the intermediate layer component and the top surfaceplane of the first pole tip higher than the top surface plane of thefront layer component; the first pole tip formed being a top first poletip; forming the front layer component with a bottom first pole tip thatis connected to the top first pole tip and is located therebelow;forming each of the top and bottom first pole tips with a front surfaceat the ABS that has a width; and forming the width of the front surfaceof the bottom first pole tip at the ABS greater than the width of thefront surface of the top first pole tip at the ABS.
 24. The method asclaimed in claim 23 including: forming the rear layer component with awidth; and forming the width of the front surface of the bottom firstpole tip substantially equal to the width of the rear layer component.25. The method as claimed in claim 23 including: forming the gap layerwith substantially flat top and bottom surfaces that extend from the ABSto the back gap; forming the common layer as a substantially flat layerwith top and bottom surfaces that extend from the ABS to the back gap;and forming each of the first and second read gap layers and the secondshield layer as substantially flat layers.
 26. The method as claimed inclaim 25 including: forming the rear layer component with a width; andforming the width of the front surface of the bottom first pole tipsubstantially equal to the width of the rear layer component.
 27. Themethod as claimed in claim 25 including: the coil formed being the onlycoil in the head; and locating the top and bottom surface planes of thecoil between the top surface plane of the intermediate layer componentand the top surface plane of the first pole tip.
 28. The method asclaimed in claim 22 including: forming the rear layer component with awidth; and forming the width of the front surface of the bottom firstpole tip substantially equal to the width of the rear layer component.29. The method as claimed in claim 27 including: locating the top andbottom surface planes of the coil between the top surface plane of theintermediate layer component and the top surface plane of the frontlayer component.
 30. The method as claimed in claim 29 including:forming the rear layer component with a width; and forming the width ofthe front surface of the bottom first pole tip substantially equal tothe width of the rear layer component.
 31. The method as claimed inclaim 25 including: the coil layer formed being a first coil layer;forming a second coil layer; forming each of the coil layers withsubstantially flat top and bottom surfaces that define top and bottomsurface planes; and locating the top and bottom surface planes of thefirst coil layer between the top surface plane of the intermediate layercomponent and the top surface plane of the front layer component andlocating the top and bottom surface planes of the second coil layerbetween the top surface of the front layer component and the top of thefirst pole tip.
 32. The method as claimed in claim 31 including: formingthe rear layer component with a width; and forming the width of thefront surface of the bottom first pole tip substantially equal to thewidth of the rear layer component.
 33. The method as claimed in claim 23including: forming the front surface of the second pole tip with asubstantially flat central portion that is substantially centered withrespect to the top first pole tip and that has first and second sideportions that slope upwardly from the central portion at an angle lessthan 90°; and locating the first and second side portions directly abovethe bottom first pole tip.
 34. The method as claimed in claim 33including: forming the rear layer component with a width; and formingthe width of the front surface of the bottom first pole tipsubstantially equal to the width of the rear layer component.
 35. Themethod as claimed in claim 34 including: the coil layer formed being afirst coil layer; forming a second coil layer; forming each of the coillayers with substantially flat top and bottom surfaces that define topand bottom surface planes; and locating the top and bottom surfaceplanes of the first coil layer between the top surface plane of theintermediate layer component and the top surface plane of the frontlayer component and locating the top and bottom surface planes of thesecond coil layer between the top surface of the front layer componentand the top of the first pole tip.
 36. The method as claimed in claim 34including: the coil formed being the only coil in the head; and locatingthe top and bottom surface planes of the coil between the top surfaceplane of the intermediate layer component and the top surface plane ofthe first pole tip.
 37. The method as claimed in claim 36 including:locating the top and bottom surface planes of the coil between the topsurface plane of the intermediate layer component and the top surfaceplane of the front layer component.